In the field of data transmission by radio beams, the radio-wave transmitters and receivers generally comprise a radio cabinet incorporating a modulator and a demodulator, a radio antenna connected to the radio cabinet and a management cabinet comprising a multiplexer and a management microcontroller connected to the radio cabinet.
In order to connect the radio antenna to the radio cabinet, the antenna and the cabinet each comprise a connecting waveguide provided at its free end with a fixing flange. The polarization of the connecting waveguides is generally either horizontal or vertical.
In order to connect two waveguides having the same two polarization directions, all that is required is to connect the two waveguides directly by fastening their fixing flanges together.
On the other hand, if the polarization directions of the two connecting waveguides are different, respectively vertical and horizontal, it is necessary to modify the polarization direction between the two connecting waveguides. For example, it is possible to use a coaxial cable or to insert a flexible waveguide between the antenna and the radio cabinet and twist the flexible waveguide into a twisted waveguide.
However, the use of flexible waveguides, which inordinately extends the distance of the antenna from the radio cabinet, significantly increases the losses.
In order to connect the antenna to the radio cabinet, while bringing them as close together as possible, it is conceivable to connect the antenna directly to the cabinet by rotating them through 90.degree., one with respect to the other. In this case, the waveguide for connecting the antenna or the radio cabinet must comprise two different fixing systems.
However, the fixing flanges of standard connecting waveguides often provide fixing holes placed in the form of a rectangle, for indexing, and therefore do not allow various orientations of the flanges when fixing them.
A twisted waveguide, intended to be inserted between the radio antenna and the radio cabinet, before use, so as to convert a vertical linear polarization into a horizontal linear polarization, or vice versa, is also known.
In this case, after the twisted waveguide has been installed, the radio antenna can no longer be subsequently replaced by a new antenna having a polarization direction identical to that of the radio cabinet unless the twisted waveguide is removed.
The invention is therefore based on a problem of connection between a radio antenna and a radio cabinet. However, the Applicant does not mean to limit the scope of its application to this particular example but, on the contrary, to extend it to any connection of two devices for a guided wave transmission such as between an upstream transmitter and a downstream connection between a downstream receiver and an upstream connection, etc.
U.S. Pat. No. 2,729,794 teaches a device for connecting two waveguides which comprises a diaphragm inserted between the two waveguides and provides a straight slot inclined at 45.degree. with respect to the polarization directions of each of the two waveguides. This diaphragm acts as means of rotation which are intended to rotate the polarization of the waves leaving one of the two waveguides. Here, the Applicant has sought to make the means of rotation have another function so as to make the two waveguides easier to connect.